Conventionally, as an AC generator for a vehicle, there is known an AC generator including a driving side bearing and a counter-driving side bearing provided on both sides of a shaft so as to rotationally support a rotor, in which the driving side bearing is directly press-fitted into a driving side bracket and is fixed to the driving side bracket by fastening a retainer with a screw (for example, see Patent Literature 1).
In the above-mentioned AC generator for a vehicle, instead of being fixed to the counter-driving side bracket by using the retainer, the counter-driving side bearing is housed inside a bearing housing portion of the counter-driving side bracket through a band made of a resin provided on an outer circumferential surface of an outer race portion therebetween so as to prevent a force for coupling the bearing housing portion and the bearing from being lowered by a difference in thermal expansion therebetween, which is generated by heat generation occurring when the AC generator for a vehicle is driven. In this manner, the outer race of the bearing is prevented from rotating with respect to the bearing housing portion by a friction force of the band.